Releasable spring-locking mechanism for rapid watercraft fin attachment

ABSTRACT

The present invention provides fin attachment devices and methods based upon the concept of vertical, instead of horizontal, locking forces for fin attachment to watercraft. In some embodiments the spring force is employed as the actual locking mechanism, and insertion and desertion forces are designed into the spring. The spring may be designed so that the insertion force is less than the desertion force.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 11/655,651, filed on Jan. 19, 2007, which claims the benefit of Provisional Patent Application No. 60/760,855, filed on Jan. 20, 2006, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to a mechanism whereby a locking force is provided to secure a fin, blade, or other device to another object, and more particularly to a spring-mediated locking device to secure a fin to a watercraft such as a surfboard, wakeboard, windsurfer, kite board, kneeboard, body board, or other related craft.

DESCRIPTION OF THE RELATED ART

Users of watercraft boards generally only have two methods of securing fins to their board. In particular, the user has to use either a set of screws or a snap mechanism, to attach the fins. The screw method may be quite time consuming for the watercraft user to practice. Additionally, screw and snap mechanisms may necessitate the use of multiple moving parts, any of which might be subject to rusting, failure, and stress fatigue.

Typically, toe and heel locking mechanisms, as described in the art, have a fin with a front end that has a detent or other feature that toes into the front end of the fin box to lock it into position. At the rear of the fin is a latch, whereby a linear spring may be used to latch the rear of fin into the fin box. A coil at one end of the spring moves into a cavity location within the fin box. The tension in the spring holds the spring coil in the fin box rear detent in order for the fin to stay engaged and in position.

Toe and heel locking mechanisms are prone to failure, as the locking forces are horizontal to the bottom plane of the watercraft. Other toe and heel variations have locking mechanism without springs. Typically, a toe is locked into position using a T-slot, or other configuration. The fin typically has a forward pin, or other attachment piece, that is usually positioned at 90 degrees from the fin box. The pin moves downward into the capture slot and the fin is then pushed forward so that the toe of the fin is locked into position. Another detent at the rear of the fin, or another T-pin or like capture piece, moves downward into the fin box slot and is locked down by a vertically moving lever or a cylindrically positioned cam lever.

Typically, in the variations mentioned above, an end-user has to provide a counter force along the horizontal plane to disengage the locking mechanisms. The reason this is undesirable is that in many watercraft situations a user might encounter such horizontal forces from the environment, for example, the watercraft fins might be exposed to such horizontal forces from contact with kelp, rocks, ropes, wood, sand, other watercraft, etc., and such contact could trigger the unwanted partial or full release of a fin. Therefore, prior art fin attachment systems may be prone to both mechanical and common use failures, and also may be too complicated to allow an user to quickly and effectively change his or her fin choices to adapt to a given situation.

SUMMARY

The present invention provides a user-friendly fin attachment mechanism for assorted watercraft that does not involve screws, snaps, and or heel and toe locking devices. According to various embodiments, the fin attachment may be based upon the concept of spring locking. Additionally, in various embodiments, the systems and methods described herein may be based on the concept of vertical, instead of horizontal, locking forces for fin attachment to watercraft. Generally, springs used in fin attachment devices are only utilized as horizontal force conductors to provide for the sliding of a fin part into a catch or snap mechanism.

In some embodiments, a spring in fin attachment system utilizes the spring force as the actual locking mechanism, wherein insertion and desertion forces are designed into the spring. In one embodiment, the spring may be designed so that the insertion force is less than the desertion force. In some embodiments, the fin box designs may not compromise the flow of water moving across the bottom of a watercraft. The fin box designs may be circular or box shaped, but one skilled in the art could envision many other shape variants.

Some example embodiments differ from previous designs in that they have almost no moving parts, and no levers or cams that may wear out. For example, in one embodiment, the only moving part is the action of the spring as it clamps around a circular gland located at the distal end of one or more pins extruded from the bottom of the fin. In some embodiments, the only potential for wear and tear issues might be with the circular canted spring located in the watercraft fin box. In some embodiments, such a spring may be easily removed and replaced within seconds.

One embodiment provides a new concept of vertical force locking versus the horizontal locking known in prior art systems. Generally, the potential of encountering a force that would push vertically against the fin while conducting watercraft related activities may be extremely low. Accordingly, in some cases, a fin of the invention might be less likely to be disconnected during such watercraft related activities.

Other features and aspects of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the features in accordance with embodiments of the invention. The summary is not intended to limit the scope of the invention, which is defined solely by the claims attached hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention, in accordance with one or more various embodiments, is described in detail with reference to the following figures. The drawings are provided for purposes of illustration only and merely depict typical or example embodiments of the invention. These drawings are provided to facilitate the reader's understanding of the invention and shall not be considered limiting of the breadth, scope, or applicability of the invention. It should be noted that for clarity and ease of illustration these drawings are not necessarily made to scale.

Some of the figures included herein illustrate various embodiments of the invention from different viewing angles. Although the accompanying descriptive text may refer to such views as “top,” “bottom” or “side” views, such references are merely descriptive and do not imply or require that the invention be implemented or used in a particular spatial orientation unless explicitly stated otherwise.

These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which:

FIG. 1 is a diagram illustrating a top perspective view of a first version of a fin box in accordance with one embodiment of the invention.

FIG. 2 is a diagram illustrating a bottom perspective view of the first version of the fin box of FIG. 1.

FIG. 3 is a diagram illustrating a top perspective view of a second version of a fin box in accordance with one embodiment of the invention.

FIG. 4 is a diagram illustrating a bottom perspective view of the second version of the fin box of FIG. 3.

FIG. 5 is a diagram illustrating a cross sectional view of a wedge shaped lip or barb being inserted into a fin cavity of a surfboard watercraft in accordance with one embodiment of the invention.

FIG. 6 is a diagram illustrating a top perspective view of a third version of a fin box in accordance with one embodiment of the invention.

FIG. 7 is a diagram illustrating a bottom perspective view of the third version of the fin box of FIG. 6.

FIG. 8 is a diagram illustrating a top perspective view of a fourth version of a fin box in accordance with one embodiment of the invention.

FIG. 9 is a diagram illustrating a bottom perspective view of the fourth version of the fin box of FIG. 8.

FIG. 10 is a diagram illustrating a side view of a fin being attached to a fin box, and more particularly, posts of the fin being inserted into the fin apertures of the fin box in accordance with one embodiment of the invention.

FIG. 11 is a diagram illustrating a cross sectional view of the post and fin aperture of FIG. 10 illustrating a first version of the attachment between the post and fin aperture.

FIG. 12 is a diagram illustrating a second version of the attachment between the post and fin aperture in accordance with one embodiment of the invention.

FIG. 13 is a diagram illustrating an example canted spring design in accordance with the invention.

FIG. 14 is a diagram illustrating an example fin plug design in accordance with the invention.

FIG. 15 is a diagram illustrating another example fin plug design in accordance with the invention.

FIG. 16 is a diagram illustrating a canted spring latch that depicts possible surf pin locations on a fin in accordance with the invention.

DETAILED DESCRIPTION

The present invention is directed toward fin attachment devices and methods based upon the concept of spring locking. In one embodiment, the fin attachment devices described herein may be based on the concept of vertical, instead of horizontal, locking forces for fin attachment to watercraft.

Before describing the invention in detail, it is useful to describe an example environment with which the invention can be implemented. One such example is that of a surfboard. A surfboard is a type of watercraft that is generally longer than it is wide. The board generally forms a buoyant deck that a surfer may stand on while surfing. It will be understood, however, that surfboards may also for used for paddling, e.g., while sitting, laying, etc. Additionally, other methods of propulsion may be attached to the surfboard, such as a sail, e.g., for windsurfing. Many modern surfboards may be made of polystyrene or polyurethane foam. The boards may be covered with one or more layers of fiberglass cloth and a resin such as polyester or epoxy resin.

Various embodiments of the fin attachment devices and methods disclosed herein may be used in conjunction with surfboards and other watercraft. In some embodiments, the fin attachment devices and methods disclosed herein are based upon the concept of spring locking. In some embodiments, the spring locking may be part of the surfboard. For example, in one embodiment, a canted spring might be part of a housing built into a surfboard. This housing might receive a shaft that may be held in place by the canted spring. In another embodiment, the canted spring might be part of the fin assembly. In various embodiments, the systems and methods described herein may be based on the concept of vertical, rather than of horizontal, locking forces for fin attachment to watercraft.

From time-to-time, the present invention is described herein in terms of these example environments. Description in terms of these environments is provided to allow the various features and embodiments of the invention to be portrayed in the context of an exemplary application. After reading this description, it will become apparent to one of ordinary skill in the art how the invention can be implemented in different and alternative environments. For example, in some embodiments, other types of watercraft, in addition to surfboards, might benefit from the systems and methods described herein.

The present invention is directed toward methods and systems for providing fin attachment devices and methods. The figures are for the purposes of illustrating a fin locking system for watercraft and not for the purposes of limiting the scope of the embodiments disclosed herein. FIGS. 1-9 illustrate four configurations of fin boxes 150, 170, 200, and 220, which are discussed further below. In some embodiments, during a machining or routing step, a corresponding fin cavity may be formed within the watercraft and exposed through an exterior skin (e.g., first side) of the watercraft to receive the fin boxes 150, 170, 200, 220. Some embodiments may also include a leash plug. In some embodiments, protective caps may be inserted into the fin apertures to prevent coating material and paint from entering the fin apertures.

As discussed above, FIGS. 1-9 illustrate four different versions of the fin box 150, 170, 200, and 220. FIG. 1 is a diagram illustrating a top perspective view of a first version of a fin box in accordance with one embodiment of the invention. FIG. 2 is a diagram illustrating a bottom perspective view of the first version of the fin box of FIG. 1. Referring now to FIGS. 1 and 2, a first version of the fin box 150 may have a round configuration. The fin box 150 has a lower portion 152 and an upper portion 154 that is coaxially aligned with the lower portion 152. The lower portion 152 may have a coarse pitched thread 156 formed on a cylindrical exterior surface 158 of the lower portion 152. The upper portion 154 may have a frusto-conical surface 160 with a radially extending flange 162. A matching fin cavity may be fit into the frusto-conical surface 160, flange 162 and the cylindrical exterior surface 158. To attach the fin box 150 to the watercraft, the thread 156 of the fin box 150 may be screwed into the fin cavity. In one embodiment, two fin cavities may be formed in the watercraft such that fin apertures 164 of the fin boxes 150 are approximately 1.5 inches apart from each other to receive corresponding posts of a fin.

FIG. 3 is a diagram illustrating a top perspective view of a second version of a fin box in accordance with one embodiment of the invention. FIG. 4 is a diagram illustrating a bottom perspective view of the second version of the fin box of FIG. 3. FIG. 5 is a diagram illustrating a cross sectional view of a wedge shaped lip or barb being inserted into a fin cavity of a surfboard watercraft in accordance with one embodiment of the invention.

Referring now to FIGS. 3, 4, and 5, a second version of the fin box 170 includes an elongated box configuration with rounded distal ends. An upper portion 172 of the fin box 170 may have a radially extending flange 174. The radially extending flange 174 includes a plurality of through holes 176 or apertures formed therethrough about the entire periphery of the flange 174. A bottom portion 178 of the fin box 170 may have a reduced size base 180 with a barb or a wedge shaped lip 182 at a bottom end of the fin box 170, as depicted in FIG. 5. It is also contemplated that the reduced sized base may have two or more (e.g., four, etc.) barbs or wedge shaped lips 182. In one embodiment, the wedge shaped lip 182 may protrude out laterally about 0.060 inches from the reduced sized base 180. The wedge shaped lip 182 is angled such that the wedge 182 permits the bottom portion 178 to be inserted into the fin cavity 190 machined into the bottom surface of the watercraft, but does not permit the withdrawal of the fin box 170 therefrom. In some embodiments, an adhesive or quick setting epoxy 192 may be applied between the fin box 170 and the fin cavity 190.

The fin cavity 190 formed in the watercraft may be sized slightly smaller than the outer periphery of the wedge lip 182 but slightly larger than the outer periphery of the reduced size base 180, as shown in FIG. 5. In some embodiments, the upper portion 172 of the fin box 170 may have a protrusion 186 that is about 0.0050″ above a top surface 188 of the radially extending flange 174. In this manner, the coating covers the flange 174 and may be flush with the protrusion. The fin box 170 may have two circular fin apertures 184 disposed through the protrusion 186. In some embodiments, these fin apertures 184 may be spaced about 1.5″ from each other to receive corresponding posts of the fin.

FIG. 6 is a diagram illustrating a top perspective view of a third version of a fin box in accordance with one embodiment of the invention. FIG. 7 is a diagram illustrating a bottom perspective view of the third version of the fin box of FIG. 6. Referring now to FIGS. 6 and 7, a third version of the fin box 200 may have a similar configuration as the second version of the fin box 170. For example, the third version of the fin box 200 may have a wedge shaped lip 202 at a bottom outer periphery of the lower portion 204. The third version of the fin box 200 may have a different configuration from the second version of the fin box 170 in that the radially extending flange 206 does not have a plurality of through holes; rather, the radially extending flange 206 has at least one annular groove 208 on its top surface.

FIG. 8 is a diagram illustrating a top perspective view of a fourth version of a fin box in accordance with one embodiment of the invention. FIG. 9 is a diagram illustrating a bottom perspective view of the fourth version of the fin box of FIG. 8. Referring now to FIGS. 8 and 9, a fourth version of the fin box 220 may have a similar configuration as the third version of the fin box 200. For example, the fourth version of the fin box 220 may have a wedge shaped lip 222 at a bottom outer periphery of the lower portion 224. In addition, a top surface of the radially extending flange 226 may have at least one annular groove 228. However, unlike the third version of the fin box 200, a frusto-conical surface 230 may join the radially extending flange 226 and the base 232.

Referring now to FIG. 10, in one embodiment, the posts 270 of the watercraft fin 272 may be attached to the fin apertures 210 of the fin box 200. FIG. 10 illustrates the third version of the fin box 200 but it is contemplated that the manner in which the posts 270 are attached to the fin apertures 210 may be employed in the other versions of the fin box 150, 170, and 220.

FIG. 11 is a diagram illustrating a cross sectional view of the post and fin aperture of FIG. 10 illustrating a first version of the attachment between the post and fin aperture. FIG. 12 is a diagram illustrating a second version of the attachment between the post and fin aperture in accordance with one embodiment of the invention. Referring now to FIGS. 11 and 12, which illustrate two versions for attaching the posts 270 of the watercraft fin 272 to the fin aperture 210 of the fin box 200, the post 270, may be sized and configured to slide within fin aperture 210 of the fin box 200.

As illustrated in FIGS. 11 and 12, in one embodiment, the outer diameter 274 of the post 270 is smaller than an inner diameter 276 of the fin aperture 210. The post 270 is also formed with a first undercut groove 278A and 278B, which circumscribes the post 270. In one embodiment, the fin aperture 210 may be formed with a second undercut groove 280, which may be aligned to the first undercut groove 278A and 278B.

In some embodiments, the undercut grooves 278A, 278B, and 280 may be cut such that the groove is less than half of the thickness of a coil in the canted-coil spring 282. In some embodiments, the undercut grooves 278A, 278B, and 280 may be cut so that the total thickness of the grooves 278A and 280 or 278B and 280 are approximately the same as the thickness of a coil in the canted-coil spring 282. The dimensions might vary from implementation to implementation; however, these dimensions may be selected so that the canted-coil spring provides enough pressure to hold, for example, a fin attached to a watercraft.

A canted-coil spring 282 may be inserted into the second undercut groove 280. In some embodiments, a canted coil spring may be a round-wire spring with inclining (canted), elliptical coils that deflect independently when compressed. The entire spring responds whenever any portion of the coil is deflected, permitting uniform loading at each contact point. By way of example and not limitation, a canted-coil spring 282 sold under the trademark BALSEAL Engineering of Foothill Ranch, Calif. may be inserted into the second undercut groove 280.

In FIG. 11, the post 270 may be inserted into the fin aperture 210 and removed therefrom by pushing and pulling the post 270 into and out of the fin aperture 210. The post 270 illustrated in FIG. 12 may also be inserted and removed from the fin aperture but requires a greater push in force and pull out force compared to the structure shown in FIG. 11. The reason is that the first undercut groove 278A shown in FIG. 11 is beveled, whereas the first undercut groove 278B shown in FIG. 12 is squared off. In use, the post 270 may be inserted into the fin aperture 210. Upon insertion, the outer diameter 274 of the post 270 pushes the canted-coil spring 282 outward until the canted coil spring 282 is seated in the first undercut groove 278A, B. The bevel of the first undercut groove 278A shown in FIG. 11 permits a user to pull the post 270 out of fin aperture 210 with less force compared to the post 270 and fin aperture 210 shown in FIG. 12.

FIG. 13 is a diagram illustrating an example canted spring design in accordance with the invention. Referring now to FIG. 13, a canted-coil spring 300 is illustrated. As discussed above, in some embodiments, the canted-coil spring 300 may be a round-wire spring with inclining (canted), elliptical coils that deflect independently when compressed. The entire spring 300 responds whenever any portion of the coil is deflected, permitting uniform loading at each contact point.

In one embodiment, the canted spring 300 includes a housing 302. The canted-coil spring 300 may be selected to fit in a groove or channel in the housing 302. Additionally, the housing 302 may be configured to receive a shaft 304. In one embodiment, the post may be part of a fin. In another embodiment, the post may be configured to be attached to a fin. The shaft 304 might include a groove 306. When the shaft 304 is inserted in the fin box 302, canted-coil spring 300 may hold the shaft 304 in place by contacting the groove 306. The example illustrated in FIG. 13 is similar to the examples illustrated in FIGS. 11 and 12, and includes various measurements and tolerances. It will be understood that this is only one possible canted-coil spring/housing example and that other canted spring sizes and shapes might be used with different housing sizes and shapes or different shaft sizes and shapes, without departing from the scope of the invention.

FIG. 14 is a diagram illustrating an example fin box design in accordance with the invention. Referring now to FIG. 14, fin box 400 is illustrated. Fin box 400 includes thread 402, which may comprise a course thread used to secure a fin receptor into a watercraft. The coarse thread might also be referred to as a “wide auger” thread. While the example illustrated in FIG. 14 includes specific dimensions, it will be understood that many other sizes and shapes of fin plugs might be used in conjunction with the invention.

FIG. 15 is a diagram illustrating another example fin box design in accordance with the invention. Referring now to FIG. 15, non-circular fin box 500 is illustrated. By using a fin plug that is not circular, e.g., fin box 500, it may be less likely that the fin box 500 will rotate. Accordingly, a fin attached to the fin box 500 will be less likely to rotated and the fin may retain some, e.g., predetermined alignment with the watercraft to which it is attached. While the example illustrated in FIG. 15 includes specific dimensions, it will be understood that many other sizes and shapes of fin plugs might be used in conjunction with the systems and methods described herein.

FIG. 16 is a diagram illustrating a canted spring latch that illustrates possible surf pin locations on a fin in accordance with the systems and methods described herein. Referring now to FIG. 16, a fin 500 is attached to a watercraft using a canted-coil spring 502 attached to a post. The canted-coil spring 502 and post 504 is dimensioned to slide into a receiving portion of a watercraft and thereby be secured in place.

The example embodiment of FIG. 16 is similar to the example embodiment of FIG. 10. As illustrated in FIGS. 10, 11, and 12, canted-coil spring 282 is positioned inside of a fin aperture 210. In this way, the canted-coil spring 282 might engage the post 270 when it is inserted into the fin aperture 210.

Returning to FIG. 16, the canted-coil spring 502 might also be attached to the post 504. In other words, the position of the canted-coil springs 282 and 502 are swapped between the two embodiments. As illustrated in FIGS. 10, 11, 12, and 16, a pair of posts 270 or 504 and canted-coil springs 282 or 502 might be used. In this way, the fin 272, 500 is less likely to rotate within its attachment mechanism when positioned on a watercraft. As illustrated in FIG. 16, a bar 506 might also be used to make the fin 500 less likely to rotate.

In another embodiment, the post(s) might be attached to a watercraft, while the receptacle that receives the posts might be part of or attached to the device to be attached to the watercraft. For example, in one embodiment, a watercraft might include a pair of posts inserted into receptacles in a fin securing the fin to the watercraft using the canted-coil springs. It will be understood that the receptacles in the fin may, in some cases be part of the fin, while in other embodiments, the receptacles might be a separate assembly attached to the fin.

The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. Likewise, the various diagrams may depict an example architectural or other configuration for the invention, which is done to aid in understanding the features and functionality that can be included in the invention. The invention is not restricted to the illustrated example architectures or configurations, but the desired features can be implemented using a variety of alternative architectures and configurations. Indeed, it will be apparent to one of skill in the art how alternative functional, logical or physical partitioning and configurations can be implemented to implement the desired features of the present invention. In addition, a multitude of different constituent module names other than those depicted herein can be applied to the various partitions. Additionally, with regard to flow diagrams, operational descriptions and method claims, the order in which the steps are presented herein shall not mandate that various embodiments be implemented to perform the recited functionality in the same order unless the context dictates otherwise.

Although the invention is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described. These example embodiments may instead be applied, alone or in various combinations, to one or more of the other embodiments of the invention. This is true whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments.

Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: the term “including” should be read as meaning “including, without limitation” or the like; the term “example” is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof, the terms “a” or “an” should be read as meaning “at least one,” “one or more,” or the like; and adjectives such as “conventional,” “traditional,” “normal,” “standard,” “known” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. Likewise, where this document refers to technologies that would be apparent or known to one of ordinary skill in the art, such technologies encompass those apparent or known to the skilled artisan now or at any time in the future.

A group of items linked with the conjunction “and” should not be read as requiring that each and every one of those items be present in the grouping, but rather should be read as “and/or” unless expressly stated otherwise. Similarly, a group of items linked with the conjunction “or” should not be read as requiring mutual exclusivity among that group, but rather should also be read as “and/or” unless expressly stated otherwise. Furthermore, although items, elements or components of the invention may be described or claimed in the singular, the plural is contemplated to be within the scope thereof unless limitation to the singular is explicitly stated.

The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent. The use of the term “module” does not imply that the components or functionality described or claimed as part of the module are all configured in a common package. Indeed, any or all of the various components of a module, whether control logic or other components, can be combined in a single package or separately maintained and can further be distributed across multiple locations.

Additionally, the various embodiments set forth herein are described in terms of exemplary block diagrams, flow charts and other illustrations. As will become apparent to one of ordinary skill in the art after reading this document, the illustrated embodiments and their various alternatives can be implemented without confinement to the illustrated examples. For example, block diagrams and their accompanying description should not be construed as mandating a particular architecture or configuration. 

1. A watercraft attachment system for releasably attaching a device to a watercraft, the system comprising: a receptacle attached to the watercraft dimensioned to releasably receive the device; and a locking spring configured to lock the device into the receptacle; wherein the locking spring is a canted coil spring.
 2. The system of claim 1, wherein the device comprises a fin.
 3. The system of claim 1, wherein the locking spring is disposed within an indention within the receptacle.
 4. The system of claim 1, wherein the locking spring is located on an indention in a post configured to be inserted into the receptacle.
 5. The system of claim 1, wherein the locking spring is located on a post attached to the device.
 6. The system of claim 1, wherein the locking spring is located on a post attached to the watercraft.
 7. The system of claim 1, wherein the locking spring is disposed within an groove.
 8. The system of claim 7, wherein the locking spring provides a locking force for securing the device in the groove.
 9. The system of claim 8, wherein the locking force provided by the spring is substantially parallel to an axis of the receptacle.
 10. A fin for a watercraft, comprising: a post having an groove; and a canted-coil spring disposed within the groove.
 11. The fin of claim 10, wherein the groove is generally circular in shape.
 12. A fin box, comprising: a lower portion comprising an attachment device, the attachment device comprising an edge configured to attach the fin box to a fin cavity; and an upper portion configured to attach the fin box to a fin.
 13. The fin box of claim 12, wherein the lower portion and the upper portion are coaxially aligned.
 14. The fin box of claim 12, wherein the edge comprises a cylindrical surface with a coarse pitched thread formed on the exterior of the cylindrical surface.
 15. The fin box of claim 12, wherein the fin box comprises an elongated box configuration with rounded distal ends.
 16. The fin box of claim 12, wherein the upper portion of the fin box further comprises a radially extending flange.
 17. The fin box of claim 16, wherein the radially extending flange further comprises a through hole configured to attach a fin to the fin box.
 18. The fin box of claim 16, further comprising a frusto-conical surface joining the radially extended flange and a base of the lower portion.
 19. The fin box of claim 12, wherein the attachment device comprises a wedge shaped lip configured to secure the fin box in the fin cavity.
 20. The fin box of claim 12, further comprising an annular groove on a top surface of the upper portion configured to couple the fin box to a fin.
 21. The fin box of claim 12, wherein the attachment device of the lower portion comprises a locking spring.
 22. The fin box of claim 21, wherein the locking spring is a canted coil spring.
 23. A releasable locking mechanism for a watercraft fin, comprising: an indention; and a locking spring; wherein the locking spring is for applying a spring force locking the fin into the indention.
 24. The releasable locking mechanism of claim 23, wherein the spring force on the locking spring is substantially vertical.
 25. A watercraft having a removable fin, the watercraft comprising: a watercraft body; a fin box disposed in the watercraft body; a removable fin disposed in the fin box; and a releasable locking mechanism, comprising: an indention, and a locking spring, wherein the locking spring is for applying a engagement force locking the fin into the indention. 